NOAA to extend rules for sonar use

The extension allows continued Navy use as long as protections for sea life are in place

Navy officials applauded plans to allow it to continue using a low-frequency sonar to search for quiet submarines, as long as it continues precautions to protect marine mammals, a spokesman said.

The National Oceanic and Atmospheric Administration announced Monday that it plans to extend current rules for use of Navy Surveillance Towed Array Sensor System Low Frequency Active Sonar, or SURTASS LFA sonar, another five years.

Without the extension, the rules would have expired Aug. 17.

"The Navy requested this action ... so we are pleased," Pacific Fleet spokesman Mark Matsunaga said yesterday.

Over the past five years, there has been "no documented evidence" that Navy low-frequency active sonar has damaged marine mammals, said Ken Hollingshead, an NOAA fisheries biologist who has worked on the issue. But NOAA still wants the Navy to continue making and reporting observations when it uses the sonar, he said.

The sonar is not used in the Hawaiian Islands, Matsunaga said. There are only two SURTASS LFA vessels in operation and they're both in the Western Pacific, he said.

The ships aren't authorized to turn on the low-frequency sonar anywhere in the Hawaiian archipelago, including the Northwestern Hawaiian Islands, Hollingshead said.

Protection measures NOAA will continue to require of the Navy for the sonar include:

» Visual lookouts, plus passive and active sonar monitoring, to ensure that marine mammals are detected before they enter an area where LFA sonar levels could cause injury.

» Shutting down LFA sonar whenever marine mammals or sea turtles are detected within a mile of the sound source.

» Not operating SURTASS LFA sonar at levels greater than 180 decibels within 12 miles of any coastlines, in designated biologically important areas, or at levels greater than 145 decibels within known human diving areas.

Those precautions over the past five years have resulted in few shutdowns, Hollingshead said.

In contrast, the sonar used in Rim of the Pacific war games every two years is a mid-frequency sonar. That sonar has been implicated by NOAA as a factor in some marine mammal groundings or other incidents, including the unusual movement of about 150 melon-headed whales into the shallow water of Kauai's Hanalei Bay shortly after RIMPAC games began in July 2004.

The Navy and environmental groups continue to battle each other in court over future uses of mid-range sonar.